Duly noted, kind sir! (I'll certainly read over the installation manual very carefully)
When I saw the relatively small size of the marker, and considering that the connections are 1/2 NPT, I assumed that the headloss through it wouldn't be too great. The entrance is pretty narrow, but it is short.
The website was quite useless:
http://www.cie-inc.com/Manufacturers...f440_specs.htm
I found most of the info here:
http://www.kingsolar.com/catalog/mfg...f44500lh8.html
(note how the picture is incorrect)
This 1 page PDF confirmed the flow range for me:
http://www.fabcoplastics.com/catalog/section4/4-15.pdf
as did this page:
http://www.burtprocess.com/phplus/pr...m&series=F-440
and this 3 page PDF:
http://www.harringtonplastics.com/Ca...n5/5_43-45.pdf
Either way, at $6.50 (+$7.50 s&h), I think I'm off to a good start.